1. Field of the Invention
The present invention relates to a silver halide color photographic light-sensitive material and, more particularly, to a silver halide color photographic light-sensitive material improved in color reproduction and color temperature dependency.
2. Description of the Related Art
Recently, requirements for the performance of color photographic light-sensitive materials have become strict increasingly, and so a demand has arisen for improvements in many-sided and total photographic characteristics, such as a high sharpness, a smooth graininess, and a vivid and high-fidelity color reproduction.
To obtain a more vivid color reproduction, so-called masking or an interlayer (interimage) effect, such as disclosed in U.S. Pat. No. 2,521,908, has been used.
The interlayer effect is described in, e.g., Hanson et al., "Journal of The Optical Society of America," Vol. 42, pages 663 to 669, and A. Thiels, "Zeitshriftfut Wissenschaftliche Photographie, Photophysique und Photochemie," Vol. 47, pages 106 to 118 and 246 to 255.
As means of enhancing the interlayer effect, there is a method of using a so-called DIR coupler which releases a development inhibitor upon reacting with the oxidized form of a developing agent. The DIR coupler is a coupler with a coupling active position to which a group which splits off from the coupling active position to achieve a development inhibiting effect or a precursor of that group is introduced. Practical examples of the DIR coupler are described in, e.g., U.S. Pat. Nos. 3,227,554, 3,701,783, 3,615,506, and 3,617,291.
U.S. Pat. No. 3,536,486 describes a method of obtaining the interlayer effect by introducing diffusive 4-thiazoline-2-thione to an exposed color reversal photographic constituting element. U.S. Pat. No. 3,536,487 describes a method of obtaining the interlayer effect by introducing diffusive 4-thiazoline-2-thione to an unexposed color reversal photographic constituting element.
JP-B-48-34169 ("JP-B" means Published Examined Japanese Patent Application) describes that a remarkable interlayer effect appears when a silver halide is reduced to silver by developing a color photographic material in the presence of a N-substituted-4-thiazoline-2-thione compound.
Research Disclosure No. 13116 (March, 1975) describes that the interlayer effect can be obtained by forming a layer containing colloidal silver between a cyan layer and a magenta layer in a color reversal photographic constituting element.
In addition, U.S. Pat. No. 4,082,553 describes a method of obtaining the interlayer effect in a color reversal photographic material with a layer arrangement which allows iodine ions to move during development. In this method, latent image-forming silver haloiodide grains are added to one layer of the material, and latent image-forming silver halide grains and silver halide grains which are surface-fogged so that the grains can be developed independently of image exposure are added to another layer, thereby obtaining the interlayer effect.
Using a DIR compound in order to improve sharpness, particularly an edge effect is presently, commonly performed. A DIR compound generally used is a DIR coupler which imagewise releases a development inhibitor through a coupling reaction with the oxidized form of a color developing agent, thereby forming a color dye.
When the DIR coupler is used, however, unclear colors result if a dye produced by the coupling reaction differs from a dye that is obtained from a main coupler, and this is unpreferred in color reproduction. To prevent this problem, it is necessary to develop DIR couplers with hues equivalent to those of main couplers of yellow, magenta, and cyan. That is, three types of DIR couplers with optimal reactivities must be developed, resulting in increases in costs for both development and synthesis. For this reason, development of a colorless compound-forming DIR compound has been desired.
The colorless compound-forming DIR compound is classified into two types, a coupling type and an oxidation-reduction type, in accordance with the way the compound reacts with the oxidized form of a color developing agent. Examples of the coupling type colorless compound-forming DIR compound are described in JP-B-51-16141, JP-B-51-16142, and U.S. Pat. Nos. 4,226,943 and 4,171,223. Examples of the oxidation-reduction type colorless compound-forming DIR compound are DIR hydroquinone compounds described in U.S. Pat. Nos. 3,379,529 and 3,639,417, JP-A-49-129536 ("JP-A" means Published Unexamined Japanese Patent Application), JP-A-64-546, and JP-A-3-226744, and DIR hydrazide compounds described in JP-A-61-213847, JP-A-64-88451, and U.S. Pat. No. 4,684,604. When the DIR compound of the above sort is applied to a color reversal light-sensitive material whose processing step includes B/W development (1st development) and color development (2nd development), it is preferable that the DIR compound release a development inhibitor in the 1st development for the reason explained below. That is, since the 2nd development aims to rapidly develop all of silver halides that are not developed in the 1st development, the silver developing rate in the 2nd development is very high. Therefore, attempting to obtain the development inhibiting effect imagewise in the 2nd development slows down the development of silver, causing the processing to become unstable in color development. For this reason, the DIR compound is preferably reacted in the 1st development. In this case, it is essential to use the oxidation-reduction type DIR compound capable of also reacting with the oxidized form of a developing agent for B/W development.
Controlling the interlayer effect by changing the silver iodide contents of silver halide emulsions contained in individual layers has also been conventionally, widely performed. As an example, JP-A-4-29238 discloses a method of enhancing the interlayer effect by increasing the silver iodide contents of low-speed layers.
Although the color reproduction, and particularly the saturation of a color photographic light-sensitive material can be improved by enhancing the interlayer effect as described above, another problem of an increase in color temperature dependency arises. The color temperature dependency of a color photographic light-sensitive material appears as a change in color balance caused by a change in color temperature due to the season, the time, or the weather when photography of color pictures is performed, or as a difference in color balance between sunny and shadow portions of an object to be photographed. When the color temperature dependency is high, the difference in color balance increases to make appropriate color reproduction impossible.
As means of improving the fidelity of color reproduction, descriptions related to mixing of couplers which form colors with different hues (to be described later) are found occasionally. However, none of these conventional methods can simultaneously achieve the two objectives, the improvement in color saturation and the improvement in color temperature dependency, that rather conflict with each other.